Auto fill

Hi hi ! Why is there an auto fill ? it says ''reduce waiting time" but NO that doesn't because if you get auto fill or one of your random teamates you're sure that this is gonna be a troll game. Because someone who play top / mid you know killer lanes and became support he gonna be mad and just farm and kill its gonna be an aweful game so why ? why is there and auto fill i prefer to wait 10 minutes each games than lose 1hour because of dodger and trolls !